Conventionally, there has been known a tank provided in an upper stage of a rocket to accumulate fuel (for example, see Patent Literature 1). A gas supply and extraction device is provided in the tank, and by supplying gas into the tank, the fuel in the tank is extracted.
Further, a propellant tank disposed in a zero-gravity environment or a microgravity environment to store propellant for a thruster of a space satellite has been known (for example, see Patent Literature 2). The propellant tank includes a tank body, and a propellant supply pipe for causing propellant to flow into the tank body so as to swirl along a circumferential direction of an inner wall surface of the tank body. Therefore, in the propellant tank, vapor-liquid separation can be performed so that an inner wall surface side of the tank becomes a liquid phase and the center side of the tank becomes a vapor phase.